The announcement marks a significant milestone in the delivery of the project, which is set to create 4,000 direct construction jobs.

RPA said in a statement it plans to formally commence the final stage of the procurement competition following a decision being made on the Metro North Railway Order application.

“RPA are pleased with the level of competition in the Metro North procurement process to date and believes that the final stage of the competition can deliver a value for money solution for the state whilst providing an important stimulus to the economy,” RPA spokesman Tom Manning said.

Under the Metro North Public Private Partnership (PPP), the private sector predominantly finances the construction of the project and this is then repaid by a service charge (availability charge) by the RPA over a 25 year period from the date that passenger services commence on Metro North.

“The consortium that will be selected to build Metro North is likely to include both Irish and international contractors and much of the work will involve local contractors, professional service firms and local workers.

“Other sectors of the regional economy are likely to benefit such as those in the construction material supplying industry. There will also be secondary spin off impacts due to the expenditure of wages in the local economy by the construction workforce,” he added.

The new 18 km heavy rail line will run from St Stephen's Green via Dublin Airport to Belinstown (north of Swords) using underground, surface and elevated tracks.

The RPA say the project will address a significant deficit in public transport infrastructure in north Dublin city and in Fingal, the fastest growing county in Ireland.

The agency say it will facilitate development in the corridor which is forecast by Fingal County Council to generate 37,000 additional jobs and more than double the existing level of economic activity and employment in the area.

“It is crucial to the continued expansion of Dublin Airport and will underpin the significant investment already made in the economic regeneration of Ballymun,” Mr Manning said.